The ERG is the method of choice for rapid phenotyping of mice with mutations in retina-related genes. This is due to its ease of use, its inherently quantitative character, and its capacity to report alterations in many functionally important features of specific retinal cell types. These cells include: rods, the dominant cell type in the retina; cones, the basis of daytime-vision; and secondary neurons with which rods and cones communicate their respective signals. Building on previous work by the investigators, the proposed research will perfect rapid protocols for quantitative phenotyping of mice with ERG components attributable to these cell types. This will include production of light stimulation standards and standard values for each measurable ERG parameter for the most widely used wild type (WT) mouse strains. Knowledge of the pupillary response is essential for quantifying retinal stimulation in most conditions, and the pupillary response provides intrinsically quantitative input/output information about the integrity of a well understood visual system circuit. Illumination rearing conditions have profound effects on murine retinal health and function in electroretinography. Therefore, pupillometry and retinal histology will be used to quantify the effects of rearing illumination history and to chart the natural developmental course of the phenotyping parameters of WT mice from 2 weeks to 1 year of age. The research program will also develop a computer-controlled, unified ERG/pupillometry apparatus, which will incorporate all necessary features for mass-phenotyping. This proposal will also address data collection, storage, analysis, dissemination, and archiving.